Blockchain development is essentially the building and upkeep of applications that run on blockchain technology. Blockchains themselves are digital record-keeping systems shared across a network of computers. Transactions are grouped and recorded in chronological order, forming a secure chain of blocks. This makes them tamper-proof and transparent, because everyone on the network has a copy of the ledger. Blockchain developers can focus on either the core systems, designing the architecture and protocols that make the blockchain work, or they can build applications on top of existing blockchains. These applications can take advantage of the security and transparency of blockchains to create new solutions in finance, supply chain management, and more.